1. Field of the Invention
The invention relates to a vehicular electric power source controller that controls the electrification of an electrical load mounted in a vehicle.
2. Description of the Related Art
A conventional air-conditioner control device detects the state of an electric power source, such as the voltage of a high-voltage battery or the like, via a battery management controller. The air-conditioner control device sends an activation signal to an air-conditioner controller in accordance with the result of the detection to activate an electrically powered compressor, and operates the electrically powered compressor to condition the air in the cabin via the air-conditioner controller that is supplied with the activation signal (e.g., see Japanese Patent Application Publication No. JP-A-8-20232). The control device of the air-conditioning device detects the state of an electric power source, such as the voltage of the high-voltage battery or the like, before the electrically powered compressor is operated. In this manner, the control device of the air-conditioning device improves the efficiency of the driving of the electrically powered compressor.
A vehicle is equipped with a plurality of electric power source supply system lines, such as an accessory electric power source, an ignition electric power, etc. In the vehicle, electrical loads that operate on an accessory electric power source, and electrical loads that operate on an ignition electric power source exist as electrical loads that are mounted in the vehicle. In order to operate these electrical loads, it is necessary to electrify the accessory electric power source and the ignition electric power source.
In recent years, there is growing desire or need to operate electrical loads on the accessory electric power source or the ignition electric power source while the vehicle is parked, in which the electric power sources are not in the electrified state. For example, if a user desires that a melody be played when the user gets into the vehicle, it is necessary to operate an audio system when the vehicle is parked. If a user desires that the temperature in the cabin be adjusted to a comfortable range before the user gets into the vehicle, it is necessary to operate the air-condition system while the vehicle is parked.
However, if the accessory electric power source or the ignition electric power source is electrified while the vehicle is parked in order to operate an electrical load that is desired to be used while the vehicle is parked, electric power is supplied also to electrical loads that do not need to be operated while the vehicle is parked. Thus, there will be wasteful consumption of the limited amount of electric power of the source, such as the battery or the like. If a construction in which an electrical load that is desired to be used while the vehicle is parked can be operated even when the accessory electric power source and the ignition electric power source are in the non-electrified state (e.g., a construction in which an electrical load that is desired to be while it vehicle is parked is constantly connected to the battery) is adopted, the wasteful stand-by current (dark current) will increase.
Even in the foregoing related-art technology, if the control device for the air-conditioning device is desired to be used while the vehicle is parked, it is necessary to electrify the accessory electric power source or the ignition electric power source while the vehicle is parked, or to adopt a construction in which air conditioner may be operated even when the accessory electric power source or the ignition electric power source is not electrified.